Higher air pollution health risk inside car, study finds

Drivers and passengers inside vehicles may be exposed to higher levels of air pollution than pedestrians on the road outside, according to research carried out using a ‘unique’ electric van carrying a mobile air quality laboratory.

The zero-emission Air Quality Monitoring Vehicle – developed by equipment firm Enviro Technology Services plc and nicknamed the ‘smogmobile’ – collected data by sampling air both inside and outside the van every minute during a two-hour journey along the M4 into central London.

And, the results presented today (February 16) found that levels of nitrogen dioxide (NO2) were on average 21% higher inside the vehicle with the windows shut than on the road outside.

The mean average concentration of NO2 outside the vehicle was 66 ugm3 (microgrammes per cubic metre), compared to the 80 ugm3 mean average inside the vehicle.

In addition, the results showed that for brief periods in central London NO2 levels inside the vehicle reached up to 350 ugm3. This is higher than the EU’s hourly legal limit of 200 ugm3 and annual mean limit of 40 ugm3.

The study results build on previous work led by King’s College London’s Dr Ben Barratt, which found that volunteers with personal pollution monitors attached to them were exposed to higher levels of air pollution inside a vehicle than those cycling or walking outside (see AirQualityNews.com story).

Commenting on the research released today, Dr Barratt, lecturer in air quality science at KCL, said: “This illustrative study adds to mounting evidence that vehicles provide little protection from harmful traffic pollution, and drivers and their passengers may even be exposed to higher levels than on the road outside.

“These initial findings highlight the urgent need for further investigation into the health risks faced by motorists and their passengers. It is especially important to understand the impacts of air pollution on professional motorists such as taxi and lorry drivers, who spend many hours behind the wheel each day.”

“The public health message is, you can’t hide from air pollution inside a car. Many people think that if you cycle or walk you are exposed to more air pollution, but levels are significantly lower at the side of a road than in traffic” – Dr Ben Barratt

Meanwhile, another study led by the University of Surrey last year also found that drivers are exposed to “dangerously high” levels of air pollution from traffic while waiting at red traffic lights with the engine left running (see AirQualityNews.com story).

KCL’s Dr Barratt advised the public to avoid driving wherever possible: “The public health message is, you can’t hide from air pollution inside a car. Many people think that if you cycle or walk you are exposed to more air pollution, but levels are significantly lower at the side of a road than in traffic.”

Enviro Technology Services

Enviro Technology Services said that diesel exhaust fumes were the “main cause” of both NO2 and fine particulate matter pollution.

“We have developed the Air Quality Monitoring Vehicle to give local authorities and researchers a powerful new tool to plan action to clean up our air and tackle one of our greatest public health challenges.” – Duncan Mounsor

The firm’s managing director, Duncan Mounsor, said: “Air pollution causes more than 50,000 deaths a year in the UK and costs the economy billions. We have developed the Air Quality Monitoring Vehicle to give local authorities and researchers a powerful new tool to plan action to clean up our air and tackle one of our greatest public health challenges.”

Mobile monitoring vehicle

According to Enviro Technology Services, its mobile electric air quality monitoring lab offers a “unique combination of features”. It gathers air quality data in real time both inside and outside the vehicle and plotting the results against GPS coordinates.

The firm claims that several of the state-of-the-art instruments on the vehicle are “more sensitive, more accurate and faster than the UK’s national air quality monitoring network”.

King’s College London’s Professor Frank Kelly, who also chairs the government’s Committee on the Medical Effects of Air Pollutants, said the availability of the monitoring vehicle was “an important step forward for the UK”.

He said: “Although London and the UK have extensive fixed site air quality monitoring sites the deployment of a mobile unit will provide instantaneous, onsite data directly relating to a multitude of air quality issues. A priority for the use of this mobile unit must be a more proactive approach to improving air quality by ensuring compliance with ambient air quality standards.”